function show() {
    bar = "123"
}
show()

console.log(bar);

function play() {
    //闭包正好就是应用了这个特性。来实现的
    let m = 20
    return () => {
        console.log(m);
    }
}
const fun = play()

fun()

ospan.addEventListener("click",function(){

})

//body.removeChild("span")
ospan.removeListener("click",function(){})
